Preheat oven to 400 degrees. Line a large baking sheet with foil.
Bake the sweet potatoes until a thin knife can be easily inserted in the center. (About 45 minutes to 1 hour.) Set aside until cool enough to handle.
Once cooled, remove the skins and mash until smooth. (About 4 cups.)
In a large bowl, combine the potatoes, sugar, cream, butter, orange juice, vanilla, salt, orange zest, cinnamon, nutmeg, mace, and cloves and beat until smooth.
Spoon the mixture into the prepared baking dish and sprinkle with the chopped pecans. Arrange the marshmallows in an even layer over the top. Bake until the marshamllows are lightly browned, about 35-45 minutes.
This can be made a day ahead, covered and refrigerated. Return to room temperature, then bake 35-45 minutes before serving.